Tank heater



Aug. 29, 1950 N. J. sTooKEY TANK HEATER Filed Dec. 29, 1947 IN V EN TOR.

BY ga? Patented Aug. 29, 1950 i H UNITED ES TANK HEATER Nelson J. Stookey, CentralflGity, .Iowa-y ApplicationDecember 29, 1947; vSerial'No- 794'5288 comme. (101.1219441),-

'Ihisf invention relatesi'to Water= heaters=--and haslparticularrelation to aheater suitable 'for -heatingfthewaterfin water tanksfandithe like;

I'nnorthern climates during the winter time, itiisfveryl desirable that stock wateringrtanks and the like be heated when the: temperaturefgoes belowffreezing so thatfiee'iwill not-form on the surface of 'thelwater in the tank and stock thereby beingJpreventedffrom' obtaining'water.

-Various devices havel heen providedi for this purpose, but such devices usually co-nsistoipip'e's or' theflike submerged' iny the tankf and usually resting on the bottom Y ofu vthe inside off th'etank, whichidevicesy are` heated byfoil orfthe like. Such devices have the dis advantage thatitheyv mustl be lightedalmost': everyr night during winter Weather s1`nce-=tl 1ey are manually controlled" andi itf is dif'- 'cultf t'o prophesy whether below-freezingtem*- peratureslwill be reachedi Eurth'er.; such devices arel expensive to constructY and maintain and luse considerable' fuel.

It, is 1 one of: the'- main objects `l of myfinvention to:` avoid" these difficultiesof" the-f priori artfand to; provide' a: device which canl be' very readily .installedt and which willr operate onlyl when `tl-ie surface, of'lthewatering tankf or ti-ie* likel actually beginsitofreezeor reaches-a temperature at which freezing will take place.

Another object' of my inventcmv` is to provide az simpie,,-durable-;; adjustable,- automatic heater Anotherobject of my invention is tof provide extremelysimple and eriecti-veways andlstructures for sealing such a device and insuring that the electric circuit, wiring and the like of the device will not short circuit through the water or shock stock or persons using such tanks.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawings and following specifications, wherein is disclosed a single exemplary embodiment of the invention, with the understanding, however, that such changes may be made therein as fall Within the scope of the appended claims, without departing from the spirit of the invention.

Figure 1 is a View in perspective of a device constructed according to one embodiment of my invention and in which a portion of the tank has been broken away to show the interior structure, and

Figure-Ticarl elevational view of the adjust@- mentiscre'w shown in thefcover or upper'hal'f of this device illustrated in Figure l, andillus'- tifatingmow this device is `sealed with respect to the tankI of "a heater.

Referring then to thev drawings: Adevice. constructed according toa preferred .embediment'l of myl invention includes a. tank electric' heating unit, such' asv that illustrated at 2, which' device is' wellknown in heating practice. unit"isiof`coursewater tight and'fis -secured place in thelbottomf of the tankJ 'by passing a-reduced portion ofthe member 2' throughi a suitable opening in the lower part of the tank and-locking itinplace by means of the washer 2c and* thenut' 2b".l-

'Electric current for energizing thisk heating element is brought into the heater tank through the conductors; indicated at l`,`whichpass through at water-tight' connection on top of the iloat which, in a=pref`errediorm, consists of an up'- struck' neck' having apair of outwardly extending, threaded ears Sa. A cap 8 is secured to the upstruck neck by means of the screws de which pass through suitable ears 8b in the cap. The cap is preferably domed, as illustrated at 3e, so that packing material may be locked securely within the cap to eiiectively seal the opening into the float.

A thermostat element, constructed according to a preferred embodiment of my invention, includes a base 4b, a bi-metal strip li, and a second strip just above this bi-metal strip, the position of which can be adjusted by means of the bolt 5 which extends through the cover of the float. This bolt is threaded at its lower end and has threaded engagement with the double ear 4a of the thermostat so that the friction of the doubleback ear will serve to hold the bolt in any position to which it is rotated. The bolt 5 thus may be adjusted so that the end 5c moves up and down to adjustably position the stationary portion of the thermostat element. I preferably employ a grommet, illustrated at E, through which the bolt passes, and this grommet has a collar 6a which nts within a cross link 6b. The cross link in turn may be forced against the grommet 6a by means of nuts on the small bolts 6c. The opening through which the bolt leads may therefore be effectively sealed by tightening the nuts on bolts 6c before assembling the device. The bolt 5 is provided with a head a and this head preferably has a bar-stop, indicated at 5b, which strikes a projection 9 of the cover of the float so that it cannot be rotated more than one turn.

In connecting the device for operation, one of the wires leading from the cable I passes to one binding post of the thermostat 4 and the other wire leads from the other post of the thermostat to one post of the heating element, as shown in Figure l. The other side of the heating element is then connected by means of a wire which forms the other conductor of the two-wire electric cord indicated at I.

The thermostatic element is so arranged that on cooling, the bi-metal 4 moves upwardly to cause the contact on the end of this member to make contact with the contact member of the stationary element to thus close a circuit leading to the heating element.

In practice, the adjusting bolt or screw 5 is rotated to a position such that when the temperature of the fluid in which the device is floating reaches a temperature just above freezing, the thermostat will close to cause the heating element 2 to be energized, thus maintaining the surface of the fluid above freezing or at least preventing suicient dissipation of heat from the liquid to prevent freezing, the heat passing ofl' from the liquid to cooler air being restored by the heat from the heating element so that the freezing process cannot be completed.

Although I have described a specic embodiment of my invention, it is apparent that modiiications thereof may be made by those skilled in the art. Such modifications may be made without departing from the spirit and scope of my invention as set forth in the appended claims.

I claim as my invention:

l. In a device of the class described, a water and air-tight tank to the bottom center of which is attached an immersion type electric heating thereon to engage a stationary contact, means for regulating the position of the stationary element including a screw passing through the cover of the tank, and means for sealing the screw in its passage through the wall of the tank.

2. In a device of the class described, a float consisting of two flattened halves having cooperating flanges, a conductor passing through the upper half, means for sealing the conductor as it passes through the half, an immersion heating unit engaged to the centerof the lower half and projecting therebelow, the terminals of the heating unit extending within the float, a thermostat within the float for controllably energizing the heating unit on reaching low temperatures, and means for regulating the thermostat including a screw passing through the upper half of the oat and engaging the thermostat.

3. In a device of the characted described, a float comprising two shallow cylindrical halves having cooperating flanged edges, an electrical conductor passing through an opening in the upper half, means for sealing the conductor in the opening, a cylindrical immersion type heater cartridge having terminals at one end thereof extending into the interior of the float through an opening located centrally of the bottom thereof. means sealing said heater in said opening, and a thermostat mounted on an interior wall of said float and connected and arranged to close an electric circuit to the heater'cartridge upon a drop in temperature.

4. In a device ofthe character described, a float comprising two shallow cylindrical, dome-shaped halves having cooperating flanged edges, a cylindrical, immersion type heater cartridge extending downwardly from the center of the lower of said float halves, the upper end of the said heater cartridge having terminals extending upwardly through an opening in the lower oat half into the interior of the float, means providing a water tight seal between the heater cartridge and the said lower oat half, an electrical conductor passing through an opening in said float, means for sealing said opening, and a thermostat within said float connected with said conductor to close an electric circuit to the heater cartridge NELSON J. S'IOOKEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,201,703 Sage p May 21, 1940 2,430,272 Brodie Nov. 4, 1947 

